Carpet dyeing method and apparatus



Feb. 1, 1966 s. KELEN ETAL CARPET DYEING METHOD AND APPARATUS 2 Sheets-Sheet 1 Filed Aug. 28, 1962 Feb. 1, 1966 s. KELEN ETAL 3 CARPET DYEING' METHOD AND APPARATUS Filed Aug. 28, 1962 2 Sheets-Sheet 2 We mwmmm WWWWI/WW/i/M United States Patent Ollice 3,231,908 Patented Feb. 1, 1966 This invention relates to the dyeing of carpets and is particularly directed to an improved method of open dyeing that has special utility for dyeing carpets made of synthetic fibres such as nylon fibres.

The problem is to dye new carpets in long lengths expeditiously and in a manner that results in level coloring of the carpet, i.e., close uniformity of color throughout the area of the carpet. tested by cutting small samples or swatches from the central region and the opposite marginal regions of an end of the carpet and then carefully comparing the samples. 1

In open dyeing a long strip of carpet with its ends temporarily sewn together to form a continuous carpet strip is run continuously through a dye solution with the carpet spread to its full width; whereas in rope dyeing the carpet is bunched in width to run through the dye solution in compact rope-like form. Both of these procedures have their advantages and disadvantages.

Rope dyeing is the more prevalent procedure because is saves time and does readily produce uniform coloring. Unfortunately, however, rope dyeing reduces the fluff of nylon carpeting to result in lowered quality. An additional disadvantage is that rope dyeing shrinks a nylon carpet to necessitate an additional stretching operation after the carpet is dyed.

On the other hand, conventional open dyeing of a nylon carpet results in a flufiier carpet than rope dyeing. In fact, open dyeing can be used to produce a nylon carpet that is flufiier than a rope-dyed carpet of the same;

weight per square yard or can be used to produce a nylon carpet that has the same quality in appearance as aropedyed carpet but is actually of less weight per square yard than the rope dyed carpet. Open dyeing, moreover, does not shrink a nylon carpet. i i

The serious disadvantage of conventional open dyeing of nylon carpets, however, is the excessive time required. The color is seldom uniform after a boiling period that would be adequate for rope dyeing and prolonged running of the carpet through the boiling solution becomes necessary to obtain uniformity. In rope dyeing, uniformity of color may be achieved within a boiling period of only 15 minutes but in conventional open dyeing it is commonly necessary to carry out the boiling operation for a period of one to three hours.

The present invention reduces the time required for open dyeing and thereby makes open dyeing comparable Such uniformity is commonly less there is considerable turbulence for continually br nging fresh solution into contact with the carpet. The dynamics of the rope dyeing procedure are highly conducive to turbulence in the dye solution because the carpet changes configuration radically and rapidly as it travels through the solution and as it is withdrawn from the solution. On the other hand, in open dyeing the configuration in width is constant and the smooth configuration of the fully spread carpet as it is drawn through the dye solution is not conducive to active turbulence.

In the second place, it has been found that when a carpet that is constantly spread to full width travels through a dye solution that is richer in dye ingredients in one part of the tank than in another part, the carpet correspondingly picks up different concentrations of dye over its width. In rope dyeing, however, the carpet is concentrated in a small area of the tank. Such uneven dye concentration may arise from various causes and is always created when dye is added to the water in the tank by the conventional procedure of introducing small quantities of the dye into differentparts of the tank.

In the third place, when a carpet is spread to full width in a tank a lesser volume of the dye solution is available per square inch of carpet in the longitudinal central region of the traveling carpet than in the two side marginal regions with the consequence that the central region tends to be lighter in color. This fact may be appreciated when it is considered that the side edges of the carpet are spaced liberally from the corresponding walls of the tank so that substantial volumes of solution are available in wide ranges of radial directions from the two marginal regions of the carpet, whereas in the central area of the carpet the solution is available only in restricted directions perpendicular to the carpet. It is also to be noted side margins are more exposed for dye absorption than a the longitudinal central region of the carpet.

in cost to rope dyeing. Thus the invention combines the advantages of both open dyeing and rope dyeing without incurring the disadvantages of either of the two pro cedures. I i

The difficulty in open dyeing is the tendency for the color to be weaker in the longitudinal central region of the carpet than in the two side marginal regions. In addition, too often the colors in the two marginal regions do not match each other. It has been discovered that these uneven color effects are inherent in the conditions which exist in conventional open dyeing as distinguished from rope dyeing.

In the first place, it has been found that since the carpet continuously absorbs dye from the solution, portions of the dye solution immediately adjacent a traveling surface of the carpet tend to become partially exhausted un- Based on this discovery of the difliculties inherent in open dyeing, the invention meets the situation by continuously pumping dye solution from the tank and returning the dye solution continuously in the form of jet streams distributed across the tank. The jet streams create violent turbulence to bring fresh dye solution continuously to the traveling carpet and to prevent any significant differences in dye concentration over the area of the tank.

A special advantage of the invention is that it is a simple matter to arrange for a greater volume of the dye solution to be returned by the jet streams in the region of the central area of the traveling carpet than in the regions of the two margins of the carpet. The jet streams in the central area may be enlarged for this purpose but we prefer to make all of the jet streams alike and to crowd more jet streams into the central region and thus equalize the volume of dye solution available in the central region with the volumes available in the two side regions.

The invention also reduces the tendency for the newly introduced dye to cause wide variations in dye concentration in the different regions of the tank. For this purpose provision is made to introduce dye constituents at the intake of the pump for intermixt-ure with the water inside the pump and in the line from the pump to the nozzle openings that produce the jet streams. Thus the newly introduced dye constituents are immediately distributed among the jet streams and the turbulence created by the jet streams quickly spreads the added material uniformly throughout the tank.

The features and advantages of the invention may be understood from the following detailed description and the accompanying drawings.

In the drawings, which are to be regarded as merely illustrative FIG. 1 is a schematic perspective view of the initial embodiment of the invention;

FIG. 2 is a view of the embodiment partly in end elevation and partly in section showing how the continuous strip of carpet is processed;

FIG. 3 is a fragmentary side elevational view showing how the jet streams are more concentrated in spacing in the central region of the tank and also showing how a support tube for a pair of spreading rollers is given the additional function of serving as a manifold to produce the jet streams;

FIG. 4 is an enlarged transverse section taken along the line 4-4 of FIG. 3 to show how the support tube is bored to provide the required nozzle openings;

FIG. 5 is a fragmentary view, partly in side elevation and partly in section, showing how a supply of the dye constituents may be connected to the intake side of the P p;

FIG. 6 is an elevational view showing how a closed rotary basket or cage may be used in the tank for dyeing yarn; and

FIG. 7 is a transverse section of the structure shown in FIG. 6.

In the construction shown in the drawings, the tank has two opposite side walls 10 and 12, two opposite end walls 14 and 15 and a cylindrically curved bottom wall 16. The two end walls 14 and 15 are extended upward to support an overhead wall 18 and to form large side openings 19 and 20 on opposite sides of the tank that extend for the full length of the tank for convenient access to the tank interior. The two side openings 19 and 20 are provided with suitable ledges 21 and 22 respectively, along their bottom edges. The tank is suitably supported with its bottom portion in a well 24 below the level of a floor 25.

A carpet, generally designated C, that is to be dyed may be a relatively short carpet, for example of a length of 90 feet, or may be a long carpet of a length of 400 feet or more. An exterior longitudinal roll 26 journalled on brackets 28 outside the side openings 29 is provided to facilitate introducing the carpet into the tank and to facilitate subsequent withdrawal of the carpet from the tank. When the carpet is fully loaded into the tank the two ends of the carpet are temporarily sewn together to make a continuous carpet strip.

The continuous carpet strip is continuously driven by a power-actuated drive roll 30 of a well known construction which has longitudinal bars 32 spaced around its circumference for contacting the carpet strip with the required driving traction. The drive roll 30 pulls the carpet strip upward and forms a loop 35 of the carpet strip above the level of the dye solution 36 in the tank.

The carpet that travels downward from the drive roll 30 accumulates in the form of a large number of folds 38 in the bottom of the tank, the major portion of the traveling carpet being stored in the form of the submerged folds at all times during the dyeing operation. As the traveling carpet strip emerges from the dye solution, it is guided by a smooth transverse support beam 40 to make contact with a spreading roll 44, the spreading roll being journalled in brackets that extend upward from the beam 46. The spreading roll 44 which may be driven in the same direction as the carpet at a slightly faster rate than the travel of the carpet strip has a spiral rib 46 (FIG. 3) on its left half that tends to spread the carpet leftward and has a similar spiral rib 48 on its right half that tends to spread the carpet rightward, the two ribs cooperating to have a lateral stretching effect on the traveling carpet. In a typical construction, the support beam 40 is in the form of a smooth stainless steel tube approximately 5 inches in diameter.

All of the structure described to this point is conventional and old in the art. The invention adds a circulation pump 50 driven by a motor 52 and gives the tubular support beam 40 the added function of serving as a fluid passage member or manifold tube for distributing the recirculated dye solution in the form of numerous jet streams 54 as indicated in FIGS. 3, 4 and 5. For this purpose the manifold tube 46 is provided with numerous nozzle elements in the form of bores 55 which are more numerous per unit length of the tube in the longitudinal middle region of the tube than in the regions near the two opposite ends of the tube that correspond to the two opposite margins of the traveling carpet.

If the bores 55 are too small and/or too few, the jet streams 54 have too high a velocity with a consequent tendency to damage the carpet. With the circulation pump 50 delivering 50 gallons per minute, the bores 55 may be W inch diameter. If the velocity is found to be too high, it is a simple matter to provide additional bores to reduce the velocity.

A pipe 56 connected to the output side of the pump 50 has a first branch 58 connected to one end of the tubular beam 49 and a second branch 60 connected to the second end of the tubular beam, the two branches being provided with corresponding valves 62 and 64. The two valves 62 and 64 are adjusted as required to equalize the flow to the two ends of the manifold tube 40 and thus equalize the jet stream flow from the two longitudinal halves of the manifold tube.

In like manner a pipe 65 connected to the intake side of the pump 50 has a first branch 66 connected to a bottom outlet 63 at one end of the tank and a second branch 70 connected to a bottom outlet 72 at the other end of the tank. These two branch pipes 66 and 79 may be provided with corresponding valves 74 and 75 for equalizing the rates of return flow through the two pipes. For the purpose of bringing the circulating water to a boil a suitable heat exchanger 77 may be connected to the pipe 56 on the output side of the pump 50 as indicated in FIG. 1.

Any suitable means may be provided to introduce chemicals and dye materials to the circulation system. As indicated in FIG. 5, the dyestuffs to be added may be placed in a container 76 with a suction tube 78 extending from the container to the intake side of the pump 50. The suction tube 78 is provided with a suitable cut-oif valve 80.

A typical dyeing procedure with the described apparatus is as follows. With a strip of carpet loaded into the tank with the aid of the exterior roll 26 and with the two opposite ends of the carpet sewn together to form a continuous carpet strip and with the tank filled with water to the level indicated in FIG. 2, the heating means is energized to raise the temperature of the water to the boiling point. In accord with the usual practice, the required chemicals are added while the water is relatively cool, say at 60 F., and the dye is added when the water reaches 100 F. In the meantime the drive roll 30 is actuated to cause the carpet strip to travel continuously into and out of the water.

The chemicals and the dye are added in the manner shown in FIG. 5 by placing the ingredients in the container 76 and opening the valve 80 to cause the material to be sucked into the intake of the pump 50. The material introduced into the intake side of the pump in this manner mingles with the water on the output side of the pump and is distributed through the manifold tube 40 to the various jet streams 54.

As the strip of carpet is drawn upward out of the dye solution in the form of the carpet loop 35 the stored portion of the carpet is progressively unfolded. The upward travel of the carpet and the unfolding of the submerged carpet tends to cause the submerged folds 38 to be drawn to the surface but this tendency is counteracted by the downward force of the jet streams 54 as may be seen in FIG. 2. It is also to be noted that the downwardly directed jet streams being directed against the submerged carpet for the full width of the carpet bring the freshly recirculated unspent dye solution into distributed contact with the, surface of the carpet.

It is to be noted that the provision of a greater distribution density of the nozzle bores 55 in the centralregion of the manifold tube 40 not only compensates, for the inherent tendency for less coloring to reach the longitudinal central portion ofthe carpet strip but also compensates for the pressure drop in the central portion of the manifold tube. 111 other words the increased number of nozzle bores 55 perunit length of the manifold tube 40 in the central region of the manifold tube is intended to compensate for the pressure drop in the manifold tube to equalize the velocity among the jet streams 54 and is intended additionally to supply more of the recirculated solution per inch width of the carpet in the central longitudinal area oftheicarpet than in recirculation of the solution by means of the numerous jet streams keeps the dye concentration uniform throughi out the solution, there being no possibility of accumulation of spent dye solutionin any part of the tank. The

use of two bottom outlets in the tank. to return the dye solution to the pump 50 is helpful for maintaining uniform dye concentration but only one bottom outlet, preferably a central bottom outlet, may be provided if desired.

After the dye solutionboils for 15 minutes with the carpet strip traveling continuously through the dye solution, samplesare cut out at the sewn ends of the carpet, one swatch being taken from the center of the carpet and twoswatches being taken from the opposite margins respectively. These swatches are carefully compared under suitable lighting. If the three swatches are uniform, the carpet may be withdrawn from the tank at this time. If the three swatches are not uniform, the boiling is continued for another 15 minutes with the carpet traveling continuously and swatches are again taken from the carpet for test. In many instances a ISniinute boiling period is enough and more than minutes is required only when certain sensitive dyes are used which require an additional 10 minutes of boiling. Before thecarpet is removed, the dye solution is drained from the tank ously pumping a poltion of the dye solution out of the tank and returning the dye solution in the form of numerous jet streams above the liquid level of the body of solution directed downward against *the portion of the submerged carpet in the tank to i i keep the portion submerged. 2. of carpet, the combination of:

a tank to' confine a body of dye solution; means to continuously withdraw a portion of the carpet from the solution with the carpet spread in width to form a traveling loop above the solution to run the carpet strip continuously through the dye solution with the major portion of the running carpet stored in folded configuration in the solution below the loop at all times; a pump having its intake side connected to the tank to continuously withdraw dye solution from the tank; and; e I a series of nozzle elements directed downward above the body of the solution inside the loop and connected to the output side of the pump to return the I dye solution to the tank in the form of jet streams distributed across the width of the carpet in the tank with the jet streams directed downward to the region of the submerged portion of the running carpet to continuously counteract the tendency of t the submerged portion of the carpet to rise to the top of the body of solution andto agitate the body of solution to promote uniformity of the dye solution.

.3, An apparatus as set forth in claim 2 in which said nozzle elements are spaced and dimensioned for a greater volume of return flow of the dye solution per foot of Width of the carpet in the central longitudinal.

region of the running carpet than in the two opposite and is replaced by clear'water for rinsing the carpet strip. The tank may be drained by connecting -a-drainage outlet (not 'shown) to a seweror the output side A further feature of the invention is that it may be employed for dyeing yarn. For this purpose, as shown in FIG. 6, a cylindrical basket or cage 82 'of open wire construction ismounted on a power actuated horizontal shaft $4 for rotation with the lower side of thev revolving cage submerged in the dye solution as indicated. The cage 82 is provided with a longitudinal closure 85 mounted on suitable hinges 86. The same operating cycle is used and with the jet streams directed downward against the revolving cage, color uniformity is quickly achieved.

Our description in specific detail of the preferredpractices of the invention will sugge'st various changes, substitutions and other departures from our disclosure within the spirit and scope of the appended claims.

We claim: 1. A method of dyeing a long length of carpet characterized by the steps of: placing a body of dye solution in a tank;

joining the ends of the carpet together to make a continuous strip of carpet and continuously running the carpet strip through the .water'by continuously withdrawing and returning a loop of the carpet strip with the major portion of the carpet strip. submerged in the tank at all times; and continuously circulating the dye solution by continumarginal regions of the running carpet.

In an apparatus for dyeing a long continuous strip of carpet, the combination of:

a tank to confine a body of dye solution;

a fluid passage member extending across the tank above the confined body of dye solution, said fluid passage member having downwardly directed nozzle outlets distributed along its length;

means to continuously withdraw a portion of the carpet strip from the body of solution to a region above the body of the solution and to continuously return the portion of the carpet strip to the body of solution to form a continuously traveling loop of the carpet strip enclosing said fluid passage member with the major portion of the running carpet in the body of dye solution; and

.a pump having its intake side connected to the tank to withdraw dye solution from the tank and having its output side connected to said pump to return the dye solution to the tank in the form of numerous jet streams distributed across the tank and across the width of the traveling carpet strip.

5. An apparatus as set forth in claim 4 in which the output side of said pump is connected to opposite ends of said fluid passage member.

6. A combination as set forth in claim 4 which includes adjustable means for controlling the division of the flow from the tank to the two opposite ends respectively of the fluid passage member for regulation to equalize the flow to the two ends of the fluid passage member.

7. An apparatus as set forth in claim 4 in which the flow capacity of the nozzle elements per longitudinal foot of the fluid passage member in the central longitudinal region of the fluid passage member is greater than in the end portions of the fluid passage member.

8. In an apparatus for dyeing a long continuous strip of carpet, the combination of:

a tank to confine a body of dye solution;

In an apparatus for dyeing a long continuous strip V means to continuously Withdraw from thebody of solution and return to the body of solution a portion of the carpet to form a running loop of carpet outside the body of dye solution;

rotary means extending across the tank to engage the carpet loop from inside the loop to spread the loop to the full Width of the carpet;

a fixed hollow member extending across the tank to support said rotary means inside the loop, said hollow member having numerous outlets distributed along its length; and

a pump having its intake side connected to the tank and its output side connected to said hollow member to continuously withdraw dye solution from the tank and return the dye solution to said outlets to form jet streams.

9. In a process of dyeing a long strip of carpet in a body of dye solution in a tank wherein the ends of the strip are connected together to form a continuous strip spread in width and a portion of the spread strip is formed into a running loop above the body of solution with the major portion of the continuous strip in the body of solution, an improvement to counteract the tendency of the carpet to color unevenly, said improvement comprismg:

continuously withdrawing dye solution from the tank and returning the dye solution to the tank with the return flow distributed across the width of the carpet and with the rate of return flow per unit measurement of width of the carpet increasing from the two regions of the opposite longitudinal edges of the carpet towards the central longitudinal region of the carpet to compensate for greater accessibility of the solution to the carpet to the regions of the longitudinal edges of the carpet than to the central longitudinal region of the carpet.

10. An improvement as set forth in claim 9 in which the return flow is formed into jets inside the running loop above the level of the body of solution directed downward to the region of the submerged portion of the carpet to counteract the tendency of the submerged portion to float on the body of the solution and to agitate the body of the solution to promote uniformity in the concentration of the solution.

11. In a process of dyeing a long strip of carpet in a body of dye solution in a tank wherein the ends of the strip are connected together to form a continuous strip spread in width and a portion of the spread strip is formed into a running loop above the body of solution with the major portion of the strip submerged in the body of solution, the improvement comprising:

continuously withdrawing dye solution from the tank and returning the dye solution to the tank above the body of solution in the tank inside the loop in the form of a series of jets distributed across the width of the carpet in the region where the running loop draws the strip from the body of solution with the jets directed downward towards the surface of the solution to counteract the tendency of the submerged carpet to float on the body of solution and to counteract the tendency of the running loop to pull the submerged carpet upward out of the body of solution.

12. In an apparatus for dyeing a long continuous strip of carpet by means of a body of a dye solution in a tank wherein a running loop of the continuous strip is formed above the body of solution by a transverse support beam in combination with a spreading roll and a drive roll, the improvement comprising:

said transverse support beam being hollow with numerous downwardly directed discharge openings distributed along its length; and p the provision of means to continuously withdraw dye solution from the tank and to force the dye solution into the interior of the support beam for continuous recirculation of the dye solution and for continuously agitating the dye solution and for applying downwardly directed force to the submerged portion of the carpet to counteract the tendency of the submerged portion to float on the body of solution. 13. An improvement as set forth in claim 13 in which the flow capacity of the distributed discharge openings per unit measurement of the width of the carpet increases from the opposite ends of the support beam to the central longitudinal portion of the support beam to compensate for greater accessibility of the solution to the regions of the longitudinal edges of the carpet than to the central longitudinal region of the carpet.

References Cited by the Examiner UNITED STATES PATENTS 1,665,624 4/1928 Conrad 6S-178 X 1,775,543 9/1930 Abbott 68189 X 2,069,311 2/1937 Hilliard 8151 2,086,298 7/1937 Isaac 8151 2,128,516 8/1938 Graham 8-151 2,441,308 5/1948 Bond 68-62 X 2,957,330 10/1960 Cline 6820 2,961,863 11/1960 Sulcek 6820 3,016,728 1/1962 Mann 68-177 3,091,109 5/1963 Clement 68177 FOREIGN PATENTS 2,019 1862 Great Britain.

OTHER REFERENCES American Dyestutl Reporter, June 25, 1951 (pp. 403 to 408, copy in Group 170).

Journal of the Society Dyers and Colorists (March 1958) (pp. to 150, copy in Group Textile Research Journal, February 1959 (pp. 134 to 143, copy in Group 170).

References Cited by the Applicant UNITED STATES PATENTS 2,163,634 6/ 1939 Schlumpf. 2,362,871 11/1944 Wardwell. 2,876,063 3/1959 Bond. 2,978,291 4/ 1961 Fahringer.

IRVING BUNEVICI-I, Primary Examiner.

CHARLES A. WILLMUTH, WALTER A. SCHEEL,

Examiners. 

1. A METHOD OF DYEING A LONG LENGTH OF CARPET CHARACTERIZED BY THE STEPS OF: PLACING A BODY OF DYE SOLUTION IN A TANK; JOINING THE ENDS OF THE CARPET TOGETHER TO MAKE A CONTINUOUS STRIP OF CARPET AND CONTINUOUSLY RUNNING THE CARPET STRIP THROUGH THE WATER BY CONTINUOUSLY WITHDRAWING AND RETURNING A LOOP OF THE CARPET STRIP WITH THE MAJOR PORTION OF THE CARPET STRIP SUBMERGED IN THE TANK AT ALL TIMES; AND CONTINUOUSLY CIRCULATING THE DYE SOLUTION BY CONTINUOUSLY PUMPING A PORTION OF THE DYE SOLUTION OUT OF THE TANK AND RETURNING THE DYE SOLUTION IN THE FORM OF NUMEROUS JET STREAMS ABOVE THE LIQUID LEVEL OF THE BODY OF SOLUTION DIRECTED DOWNWARD AGAINST THE PORTION OF THE SUBMERGED CARPET IN THE TANK TO KEEP THE PORTION SUBMERGED, 